-
Featured Project
Cottage Point House
-
General Resources
-
Why Wood Articles
-
What is...
Across the grain
The direction at right angles to the length of the fibres and other longitudinal elements of the wood.
Southern Mahogany | Eucalyptus botryoides
Southern Mahogany is an excellent timber for indoor and outdoor applications with a deep pink to red brown heartwood.
Southern Mahogany is a native Australian hardwood popularly used for indoor and outdoor applications as well as furniture and cabinetry.
Other Names: Bangalay (NSW), Gippsland Mahogany (Vic), Woollybutt, Swamp Mahogany or Mahogany Gum.
Overview
Southern Mahogany is a large, fast-growing species indigenous to coastal south eastern Australia, from Bairnsdale in Victoria to north of Newcastle in NSW. It is closely related to Sydney Blue Gum and is valued for its rapid growth, tolerance of frost and striking red wood.
An excellent timber tree, it has deep pink to red-brown heartwood with distinctively paler sapwood. The timber is hard, strong and dense with a medium, even texture and interlocking grain. It is durable and lyctid borers rarely attack the sapwood.
Southern Mahogany seasons readily. It turns, machines, and glues well but can blunt knives and saws more quickly than other eucalypts. It is prone to severe growth stresses when young and should be quarter sawn to reduce damage. It can be difficult to dry and air-drying in protected stacks can reduce its susceptibility to end splitting and collapse.
The timber is used in cabinetry, furniture, flooring, decking, and veneer applications as well as general construction, poles and firewood. Historically it was used in heavy construction for sleepers and posts.
Properties
Shrinkage
| Very Low | Low | Medium | High | Very High | |
Tangential: |
|||||
| 9.8 | |||||
| Radial: | > 5 | ||||
| Unit Movement: |
0.37 % |
Strength Group
| Very High | High | Reasonably High | Medium High | Medium | Reasonably Low | Low | Very Low | |
| Unseasoned: | S1 | S2 | S3 | S4 | S5 | S6 | S7 | |
| Seasoned: | SD1 | SD2 | SD3 | SD4 | SD5 | SD6 | SD7 | SD8 |
Stress Grade
| Structural No. 1 |
Structural No. 2 |
Structural No. 3 |
Structural No. 4 |
Structural No. 5 |
|
| Unseasoned: | F27 | F17 | F14 | F11 | F8 |
| Seasoned: | F27 | F22 | F17 | F14 | F11 |
Density per Standard
| Unseasoned: | 1180 kg/m3 |
|---|---|
| Seasoned: | 910 kg/m3 |
Joint Group
| Very High | High | Reasonably High | Medium | Low | Very Low | |
| Unseasoned: | J1 | J2 | J3 | J4 | J5 | J6 |
| Seasoned: | JD1 | JD2 | JD3 | JD4 | JD5 | JD6 |
Colour
| White, yellow, pale straw to light brown | Pink to pink brown | Light to dark red | Brown, chocolate, mottled or streaky | |
Mechanical Properties
| Modulus of Rupture - Unseasoned: |
84 |
|---|---|
| Modulus of Rupture - Seasoned: |
130 |
| Modulus of Elasticity - Unseasoned: |
15 |
| Modulus of Elasticity - Seasoned: |
18 |
| Maximum Crushing Strength - Unseasoned: |
46 |
| Maximum Crushing Strength - Seasoned: |
77 |
| Impact - Unseasoned: |
18 |
| Impact - Seasoned: |
18 |
| Toughness - Unseasoned: |
Medium - 15 - 25 Nm |
| Toughness - Seasoned: |
Medium - 15 - 25 Nm |
| Hardness - Unseasoned: |
7.0 |
| Hardness - Seasoned: |
9.0 |
Durability
| Low | Moderate | Reasonably High | High | |
| (0 - 5 yrs) | (5 - 15 yrs) | (15 - 25 yrs) | (more than 25 yrs) | |
| In-Ground: |
||||
| (0 - 7 yrs) | (7 - 15 yrs) | (15 - 40 yrs) | (More than 40 yrs) | |
| Above ground: |
||||
| (0 - 20 yrs, usually < 5) | (21 - 40 yrs) | (41 - 64 yrs) | (More than 60 yrs) | |
| Marine Borer Resistance: |
| Lyctid Borer Susceptibility: |
Not Susceptible |
|---|---|
| Termite Resistance: |
Resistant |
Fire Properties
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | |
| EFH Ignitibility: |
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
| EFH Spread-of-Flame Index: |
|||||||||||
| EFH Smoke-Developed Index: |
| 1 - non-combustible | 2 - reasonably non-combustible | 3 - slightly combustible | 4 - combustible | |
| Fire Properties Group Number: |
| Group Number - Other: | 3 if used on MDF or particleboard ≥12mm; veneer thickness 0.6-0.85mm |
|---|---|
| Average Specific Extinction Area: |
<250 |
| Bushfire Resistance: |
BAL 12.5 and 19 – All AS3959 required applications |
Description
| Botanical Name: | Eucalyptus botryoides |
|---|---|
| Preferred Common Name: | Southern Mahogany |
| Other Names: | Bangalay (NSW), Gippsland Mahogany (Vic), Woollybutt, Swamp Mahogany or Mahogany Gum. |
| Species Type: | Hardwood |
Appearance
Southern Mahogany features deep pink to red-brown heartwood with a distinctively paler sapwood. The timber is hard, strong and dense with a medium, even texture and interlocking grain.
Common Applications
The timber is used in cabinetry, furniture, flooring, decking and veneer applications, as well as general construction, poles and firewood.
Common Form
Sawn
Workability
Southern Mahogany seasons readily. It turns, machines and glues well but can blunt knives and saws more quickly than other eucalypts. It is prone to severe growth stresses when young and should be quarter sawn to reduce damage. It can be difficult to dry.
Origin of Timber
NSW, VIC
Readily Available
NSW
Availability - Further Information
Southern Mahogany is relatively common on the south coast of NSW.
Source of Timber
Native Forest
Applications
-
Architectural Roof Trusses
Architectural timber roof trusses create strong visual impact. Often used as part of ‘cathedral ceiling’ systems, timber can be specified light or heavy to suit the chosen theme and style. On finish, they can be left natural or may be oiled, stained, painted or highly decorated. Choice is limited only by individual style and design preferences.
-
Decking
Timber decking creates spaces that are functional, practical and aesthetically pleasing. With the right design and care a timber deck will make a valuable addition to any home or business, creating an outdoor living space that will be enjoyed for years to come.
-
Flooring
Whether for structural or finished flooring applications, timber offers durability, versatility and adaptability. The warmth, strength and natural beauty of timber flooring has proved enduringly popular in a wide variety of interior settings.
-
Structural Timber Poles
Timber poles are utilised in structural construction to provide support for gravity loads and resistance against lateral forces. Not only serving a structural function, timber poles provide many aesthetic benefits, with their use in construction often complementing architectural designs aimed at harmonisation with the natural environment.
-
Timber Joinery Products
Timber joinery products offer a classic, unique and stylish touch to any interior design.
-
Timber Portal Frames
For buildings that require large spans and column free interiors, timber portal frames provide one of the most aesthetically pleasing solutions. Utilising modern engineering technology, portal frame design transforms timber into a highly effective, efficient and economical structural product. This application guide provides a comprehensive overview of the process of using timber in the specification, fabrication and erection of portal frame structures.
All Comments (0)